Effect of the Flow Rule on the Bearing Capacity of Strip Foundations on Sand by the Upper-Bound Limit Analysis and Slip Lines

2014 ◽  
Vol 14 (3) ◽  
pp. 04014008 ◽  
Author(s):  
Mehdi Veiskarami ◽  
Jyant Kumar ◽  
Fatemeh Valikhah
Keyword(s):  
Bearing Capacity ◽  
Upper Bound ◽  
Limit Analysis ◽  
Flow Rule ◽  
Slip Lines ◽  
Upper Bound Limit Analysis

scholarly journals A bubble-enhanced quadrilateral finite element for estimation bearing capacity factors of strip footing

2021 ◽  
Vol 15 (2) ◽  
pp. 77-89
Author(s):  
Vo Minh Thien
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Upper Bound ◽  
Limit Analysis ◽  
Optimization Problems ◽  
Plastic Material ◽  
Strip Footing ◽  
Flow Rule ◽  
Upper Bound Theorem ◽  
Quadrilateral Finite Element

In this paper, a computational approach using a combination of the upper bound theorem and the bubble-enhanced quadrilateral finite element (FEM-Qi6) is proposed to evaluate bearing capacity factors of strip footing in cohesive-frictional soil. The new element is built based on the quadrilateral element (Q4) by adding a pair of internal nodes to solve the volumetric locking phenomenon. In the upper bound finite element limit analysis, the soil behaviour is described as a perfectly plastic material and obeys associated plastic flow rule following the Mohr-Coulomb failure criterion. The discrete limit analysis problem can be formulated in the form of the well-known second-order cone programming to utilize the interior-point method efficiently. The bearing capacity factors of strip footing and failure mechanisms in both rough and smooth interfaces are obtained directly from solving the optimization problems and presented in design tables and charts for engineers to use. To demonstrate the accuracy of the proposed method, the results of bearing capacity factors using FEM-Qi6 were compared with those available in the literature. Keywords: limit analysis; bearing capacity factors; strip footing; SOCP; FEM-Qi6.

Vertical uplift capacity of horizontal anchors using upper bound limit analysis and finite elements

2008 ◽  
Vol 45 (5) ◽  
pp. 698-704 ◽  
Author(s):  
Jyant Kumar ◽  
K. M. Kouzer
Keyword(s):  
Finite Elements ◽  
Upper Bound ◽  
Limit Analysis ◽  
Friction Angle ◽  
Soil Mass ◽  
Flow Rule ◽  
Uplift Capacity ◽  
Collapse Load ◽  
Upper Bound Limit Analysis ◽  
Associated Flow Rule

The vertical uplift capacity of strip anchors embedded horizontally at shallow depths in sand is examined by using an upper bound limit analysis in conjunction with finite elements and linear programming. Velocity discontinuities were allowed along the interfaces of all the elements. The plastic strains within elements were incorporated by using an associated flow rule. The collapse load was expressed in terms of a nondimensional uplift factor Fγ, which was found to increase continuously with an increase in both embedment ratio (λ) and the friction angle (ϕ) of sand. Even though the analysis considers the development of plastic strain within all elements, however, at collapse, the soil mass just above the anchor was found to move as a single rigid block bounded by planar rupture surfaces making an angle ϕ with the vertical. The results were found to be almost the same as reported in the literature for those based upon a simple rigid wedge mechanism.

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